Joyner said ShotSpotter’s gunshot-detection technology encompasses about 13 square miles of city streets. After a gunshot is recorded, ShotSpotter determines the geographical location and sends an exact map location directly to patrol officers.

The alert often includes an audio recording of the gunshots so officers are better prepared for the situation.

But while crime is trending down, Oakland is still one of the Bay Area’s most dangerous cities. And residents’ mistrust of the Police Department remains high after the 1999 Riders police brutality scandal, which led to ongoing federal oversight of the agency.

When Oakland brass analyzed ShotSpotter alerts in a high-crime neighborhood, they found citizens rarely called about the gunshots. A city audit last year found that citizens only called police in 13 percent of gunfire incidents, whereas ShotSpotter alerted police 98 percent of the time.

The majority of gunshots last year were recorded in East Oakland east of 73rd Avenue and south of MacArthur Boulevard, according to ShotSpotter.

“People in that community are living under siege,” Joyner said. “They don’t feel comfortable and don’t trust police — to the point they’re not even calling anymore.”

If police continued to use 911 calls to mark “hot spots” of gun violence they’d be missing the bigger picture, Joyner said.

Ralph Clark, ShotSpotter’s CEO, said the technology can be used by savvy police agencies to cultivate better relationships in their communities.

Police in Oakland, where Clark also lives, are great at responding to ShotSpotter calls and keeping detailed reports, which are helpful in criminal prosecutions.

But the fact that almost 90 percent of Oakland citizens don’t call the police after hearing gunshots is a serious “marketing issue for the OPD,” Clark said.

Officers investigating gunfire should knock on a few doors and make sure families are OK, especially in the neighborhoods where violence is rampant, Clark said.

Residents in more affluent neighborhoods expect that kind of service from police, he said, and “so should the people who live near the Oakland Coliseum.”

Joyner said he’s spent most of his career working in East Oakland, and improving community outreach is a constant goal and challenge. But the progress means the department’s community-oriented policing strategy is working, he said.